Americans themselves are almost evenly split over who they perceive to be the premier global economic heavyweight: 40 percent say the US, 41 percent say China. (Interestingly, the Chinese have no such illusions about themselves – they put America ahead by a margin of 48 to 29.)

Europeans seem most overawed by the China hype, with 62 percent of Germans putting China at the top of the heap, compared with just 13 percent who still see America as the world’s top economic power. In Britain the split is 58-28, in Spain it’s 57-26.

Worldwide, 42 percent of respondents put China ahead of America; 36 percent perceived it the other way around.

That 42 percent of respondents are off the mark. There are different ways to measure the size of a national economy, but even using the system most generous to the Chinese, called Purchasing Power Parity (PPP), the US economy was nearly half as big again as its nearest rival, the Chinese one, in 2010, according to the IMF. US Gross Domestic Product weighed in at $14.5 trillion against China’s $10.1 trillion, according to the September 2011 IMF report.

If you go by straightforward GDP, America’s economy is two-and-a-half times as big as China’s according to the World Bank. And if you compare personal wealth, well, there is no comparison.

America’s per capita GDP came in at nearly $50,000 last year, while China’s was just over $8,000 at the most generous estimate – about the same as Ecuador and Belize.

Of course you could use other criteria than mere size to judge which nation is the world’s leading economic power; innovation, for example.

But China still lags well behind the US in that field too. And when it comes to how much each country has invested abroad, Americans account for 20 percent of global foreign direct investment and the Chinese for only about 1.5 percent.

When it comes to energy, dynamism, and growth potential, the Chinese do look more impressive. And, of course, China’s population is five times bigger than America’s. At current growth rates, China probably will have the biggest economy in the world (measured on the basis of PPP) within 15 years.

But it hasn’t happened yet, whatever people around the world may believe.